\section{Ontology-building tools: an overview}
To apply the available technologies and actually build models (ontologies) of the real world, a set of easy to use tools to minimize manual labor is essential. \newline

In this section we are going to present a selection of ontology-building tools. The software presented ranges from open-source solutions (Prot\'{e}g\'{e}, NeOn Toolkit) to commercial tools (Topbraid Composer, Collibra, OntoStudio). The last part of this section concentrates on open-source tools which have a collaborative nature (myOntology, Semantic MediaWiki, IkeWiki, Kiwi).